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Re: Asilisaurus kongwe, the Oldest Avian-line Archosaur and the Early Diversification of Ornithodira



On Wed, Mar 3, 2010 at 11:11 AM, Raptorial Talon
<raptorialtalon@gmail.com> wrote:
> "Phylogenetic analysis places Asilisaurus kongwe gen. et sp. nov. as
> an avian-line archosaur and a member of the Silesauridae, which is
> here considered the sister taxon to Dinosauria."
>
> Wait . . . what? How can something be "avian-line" if it's not part of
> the clade ancestral to Aves?

A clade is an ancestor and all of its descendants, so a clade can
never be ancestral to a taxon -- it can only include (or overlap with)
other taxa.

I agree that the term "avian-line" is confusing -- I'd usually
interpret it as "ancestral to Aves", i.e., the avian lineage, but in
this context they are clearly using it to refer to the avian total
clade (otherwise known as "Avemetatarsalia", "Panaves", or
"Pan-Aves"). "Avian-branch" might be a little clearer.

So, this is the earliest known member of the avian total clade, i.e.,
avians and everything closer to them than to anything else extant.
-- 
T. Michael Keesey
Technical Consultant and Developer, Internet Technologies
Glendale, California
http://tmkeesey.net/